In accordance with development of microfabrication of semiconductor devices, increases in interconnect resistance due to interface inelastic scattering of electrons have become problematic. To overcome this problem, the use of a graphene interconnect has been proposed. Graphene exhibits ballistic conduction and little interface scattering of electrons. Accordingly, when the graphene interconnect is microfabricated, increases in resistance due to interface scattering will little occur.
However, in the graphene interconnect, six-membered rings formed of carbon atoms are continuously arranged along the surface of a substrate, which significantly strengthens the bonding of the carbon atoms. Accordingly, when a via conducting portion is provided on the graphene interconnect, the contact resistance therebetween will inevitably increase.
In view of the above, there is a demand for reducing the contact resistance between the graphene interconnect and the via conducting portion to realize a low-resistance interconnect structure.